She called me today. She was tired, she said, of being alone. I knew what it took her to call and ask a favor, and of course my answer was yes, come quickly. There was soup for lunch, and then she needed a nap, and I settled her into the guest room and tucked her in as I once did my children, pulling the blanket up to her ears and tiptoeing down the hall. The silence that settled was nearly palpable as she lay tangled in dreams and I sat trying to sort this new bend in the road of our friendship. We who had shared everything from first job to first child, we who could sit on the front steps and settle the world's problems in an evening, we who agreed on nearly everything important but what made up a pizza topping and whether Jane Austen was a necessary adjunct to the well-lived life, we who'd cried in movies and laughed over lunches for years together, were moving apart. She'd embarked on a long, slow, and certain end to her life. I was square in the middle of mine.

There must be something we can do, I'd thought, when she first told me. I've always been the kind of person with bookshelves of directories, an Internet-site list that doesn't quit, and little pieces of paper that shower from my diary with scribbled phone numbers of therapists, doctors. Have you tried this? What about that? I asked her, and stuffed envelopes with clippings and dropped books on her doorstep. And she nodded and smiled, and I'd find them unread in the hall when I arrived with a casserole and a bottle of wine. She'd laugh at my offerings—bath salts, when she was a shower person, the book of encouraging verse, when we'd once howled at sentiment. I wanted to fix it. When I couldn't, I fixed cookies.

As the weeks went on, I was all bustle and she was silent. We were reticent where once we were fluent. She knew things I didn't know, I was afraid of intruding; the easy assumptions of friends' shared space had vanished. Never before had I felt the force of the expression "in rude health"—my own sturdy self seemed to me like an affront to her. Would I say the wrong thing? Better to say nothing at all, I thought and subsided, reduced to answering-machine messages and cheery cards in the mail, and so the silence grew. A week went by, then another, till the phone call came. Where are you? I miss you, she said, and I admired the grace in the act, the hand across the widening gap. I climbed on the bus, holding the flower that had seemed irresistible at the corner, just one, a rose that spoke of summer. I was up against it—what did I have to offer if I couldn't offer a cure? I waited at her door, twirling my flower, tongue-tied again. But she was there, and she was smiling. Come keep me company, she said. I've missed you.

And so, in fits and starts, we began to make a different friendship, this one based on bedrock. For when you can't mend what is broken at the center of a friend's life—whether it's the marriage that's gone forever or the lost child or the vanished job—you learn a deeper truth, how to accept the unacceptable and, however slowly, move along together. In the end, all I have to offer is, perhaps, a little comfort as the waters rise.